[Acer Iconia A500] sirzen:
For those who want a tutorial, here's my experience in installing the system:

(PS: FOR those who want a really simple command-by-command tutorial, please see #26 post. That's part 1 of the tutorial on how to boot ubuntu up without wireless. If you need wireless working and want a command-by-command tutorial on that, just reply and I'll make it. )

I mainly referred to sp3dev's thread: http://xdaforums.com/showthread.php?t=1158260

I've make ubuntu run on my iconia, but I cannot let bluetooth run so you'd better have a usb keyboard and (if you could find the trick to use the touch screen, no need of) a usb mouse.

Tools to prepare:

1. Ubuntu OS on PC with adb tool.

2. A >=4GB microSD card and make sure iconia can identify it.

3. USB keyboard and USB mouse

4. rooted iconia with acer recovery installer, busybox, terminal emulator.

5. Perhaps more that I didn't listed

Files to download:

1. rootfs: http://www.dmmhosting.co.uk/tegra-rootfs.tar from Digitaldaz;

2. precompiled header: http://www.mediafire.com/?ucvk6x66129igzc from sp3dev;

3. itsmagic: http://xdaforums.com/showthread.php?t=1121543&highlight=itsmagic from sc2k;

4. source code: https://github.com/astarasikov/iconia-gnu-kernel from sp3dev;

5. Perhaps more that I didn't listed

Procedure to install ubuntu:

1. Use your computer to format your microSD card into two partitions: one is in FAT32, to be used as normal external storage. Suggested minimum size is 1GB, to store backup file in step 2. The other is ext4, to store root filesystem of ubuntu. Suggested minimum size is 3GB. Tools: fdisk, mkfs.vfat, mkfs.ext4. Using sudo when making filesystem. Refer to rkaszala's post for further information: http://xdaforums.com/showthread.php?t=1158260&highlight=itsmagic&page=12

(Comment: I use computer to format while he/she uses iconia to format.)

Make sure the formatted sdcard can be recognized by iconia as /dev/block/mmcblk1p1 and /dev/block/mmcblk1p2 .

2. Backup all data using itsmagic link above. Be familiar with usage of itsmagic, esp. use it to recalculate the checksum.

3. use tools here: http://xdaforums.com/showthread.php?t=1126364 to flash the newrec.img file onto the /dev/block/mmcblk0p1, and use itsmagic to recalculate checksum.

3.1. on android system, use terminal emulator to copy /system/etc/nvram.txt out as bcm4329-fullmac-4.txt .

4. USING SUDO to unzip the rootfs tarball referred in Files:1 into the ext4 fs mentioned in step 1. If you do not use sudo, some device nodes will not be able to be created.

5. SUDO EDIT the etc/fstab IN YOUR UNZIPPED ROOT FILESYSTEM NOT IN YOUR OWN UBUNTU SYSTEM to one line:

proc /proc proc defaults 0 0

6. compile source code using instructions by sp3dev here: http://xdaforums.com/showthread.php?t=1158260&highlight=itsmagic&page=9 in the middle part of the page.

7. copy the compiled bcm4329-fullmac-4.bin firmware (should be at lib/firmware/brcm/) to sdcard's root filesystem's location: /lib/firmware/brcm/ folder and copy the previous bcm4329-fullmac-4.txt here.

8. copy the compiled modules into sdcard's root filesystem's /lib/modules/ (I forget the name of the folder so be sure to name it correctly. )

9. insert the sdcard into iconia and reboot with wolume down key pressed (the way to boot into recovery img.)

and now, you should have reached what I have reached.

If you failed on some step please tell me. All I summarized is what I have done, so please refer to their original post for more information.